Backgrounds: Inhaled corticosteroids (ICS)/inhaled long-acting beta(2)-agonists (LABA) combination drugs are widely used for the long-term management of chronic obstructive pulmonary disease (COPD). However, COPD is a heterogeneous condition and treatment with ICS is associated with a higher risk of pneumonia. The identification of a specific marker for predicting the efficacy of ICS/LABA on pulmonary function would be useful in the treatment of COPD.
Methods: Fourteen COPD patients receiving tiotropium therapy participated consecutively. The relationship between the baseline exhaled nitric oxide (FE(NO)) levels as well as serum markers and changes in pulmonary function by fluticasone propionate (FP)/salmeterol (SAL) were analyzed.
Results: FP/SAL therapy significantly improved forced vital capacity, forced expiratory volume in 1 s (FEV(1)), and the third phase slope of the single nitrogen washout curve (ΔN(2)) as well as the FE(NO) level. The baseline FE(NO) levels and positive specific IgE (atopy+) were significantly associated with airway obstructive changes assessed by FEV(1) and ΔN(2). A baseline FE(NO) level >35 ppb yielded 80.0% sensitivity and 66.7% specificity for identifying the subjects with significant improvement in FEV(1) (greater than 200 mL). An atopy+ yielded 60.0% sensitivity and 88.9% specificity for an improvement in FEV(1). When combined with FE(NO) > 35 ppb and atopy+, it showed 40% sensitivity and 100.0% specificity for FEV(1) improvement. Alternatively, COPD subjects with FE(NO) ≤ 35 ppb and atopy- did not show significant improvement in FEV(1).
Conclusion: Combining FE(NO) and specific IgE may be a useful marker for predicting the response to ICS/LABA on airflow limitation in COPD.
Keywords: airflow limitation; airway inflammation; atopy; exhaled nitric oxide; inhaled corticosteroid; inhaled long-acting beta2-agonist.